“…I do have a pair of skinny jeans in my closet,” she said, before asking for audience members to identify themselves if they own a pair of skinny jeans that they use as a low-tech way to track their fluctuations in weight. A significant number of hands went up, among both men and women conference attendees.

The skinny-jeans example illustrated that the self-tracking movement, a community that uses apps, spreadsheets, journals and devices to collect a range of personal-health data, may be larger than one might think. Hitting home this point, Fox shared new national survey data from a forthcoming Pew Internet & American Life Project report. A few highlights from her findings:

60 percent of American adults track their weight, diet or exercise routine

One in three use a notebook or journal to track personal health data and one in five use an app, spreadsheet or other tool

34 percent of self-trackers say their collection of data has affected a health decision

40 percent of self trackers say their efforts have led them to ask a doctor a new question or seek a second opinion

46 percent of self-trackers say it has changed their overall approach to health

One in three self-trackers share their records or notes with someone else

Fox noted that the results of the full report, which is expected to be made available in December, show the potential of the self-tracking movement and its tools to help patients improve their health. “These are the self-trackers that are doing this under the radar without encouragement and this is the impact they are seeing,” she told the group.